This invention relates to a switch device which is so designed that its operating knob is held at the neutral position with a slider.
The arrangement of a conventional switch device of this type will be described with reference to FIGS. 3 and 4.
As shown in FIG. 3, an operating knob 3 with an articular recess 2 is mounted over a base body 1 in such a manner that it is swingable about a shaft 1a. The base body 1 has a cylindrical portion 1b, in which a compression spring 4 is accommodated. A slider 5 is mounted on the top of the compression spring 4. More specifically, the slider 5 is set as follows: The base end portion of the slider 5 is fitted in the cylindrical portion 1b of the base body 1 with a suitable clearance therebetween, and the upper end portion is engaged with the articular recess 2. The slider 5 is urged by the compression spring 4 to hold the operating knob 3 at the neutral position as shown in FIG. 3.
When the operating knob 3 is swung, the slider 5 is pushed by the sloped surface 2a of the articular recess 2, so that the slider 5 is moved downwardly along the inner surface of the cylindrical portion 1b while the outer cylindrical surface of the base end portion of the slider 5 is being guided by the inner cylindrical surface of the cylindrical portion 1b. As a result, an operating piece 6 is depressed by a depressing piece 3a of the operating knob 3, so that contact means (not shown) is turned on.
In the above-described switch device, the base end portion of the slider 5 is loosely fitted in the cylindrical portion 1a of the base body. Therefore, when the slider 5 is vibrated about its base end portion as shown in FIG. 4, the operating knob 3 engaged with the upper end portion of the slider 5 is greatly vibrated.
If the operating knob 3 is greatly vibrated in the above-described manner, then the vibration impedes its smooth operation. Moreover, in the case where the switch device is employed as a power window regulator switch in an automobile, it will produce abnormal noises as the automobile travels.